if Catholicism is from Jerusalem, why are the catholics called roman catholics?

if Catholicism is from Jerusalem, why are the catholics called roman catholics?

because their religion is and has been centered in the Vatican.

only some Catholics are called Roman Catholics. They're called that because they follow what the Pope says, and he's in Rome. Technically Vatican City, but Vatican City sits inside of Rome

When the Roman Empire converted to Catholicism everyone in the Empire became Roman Catholic.

Catholicism was formulated in the roman empire and has nothing to do with Jerusalem and true Christianity.

Duhhhhhhhh...because the church is in Rome?

because Catholicism is from Rome, only the early Christians centered their religion around Jerusalem, and they were very different from Roman Catholics, and resembled Jews in the principles of their religion.

Catholocism originated with Rome, not Jerusalem. The pagan emperor Constantine worshiped the pagan queen of heaven cult, he then changed it into the cult of Mary, with idols, holy water and other pagan rituals. This, with some christian beliefs became the roman church.

That's where the pope was, when they made up the name. As opposed to the other part of Christendom which was based in Byzantium/Constantinople.

I thought Antioch was where Christianity was first called Christianity
also,
I think the Coptic Church has it's own Pope and it's own Saints

Are you referring to Jesus being crucified at Golgotha and becoming the Christ when He rose from the dead?

The term Roman came about during the reformation. The reason Luther and the others wanted to use the term Catholic. The true name of the Roman Catholic Church is the Catholic Church it matters not where the Pope is located.

Just a little more history protestants like to ignore and make believe does not exist.

First, Papalism isn't from Jerusalem. The schism arose in Rome, under the leadership of the schismatic Patriarch of Rome, that is, the Pope of Rome. This schism abandoned the true Church in the 11Th century.

After Peter went to Rome, the leader of the Apostles were re-chosen and remained there. Later this figurehead was called the pope which originally meant "father".

The first true Christians were all Jews, later some Syrians and Turks.

Catholics are not saved and are not Christians. Catholics believe a false gospel of works that leads to eternal hell (Galatians 1).

The apostle of Christ were sent on missions after his death--one of these was to Rome, where the Church of Rome was established.

I am eternally grateful to the early Christians; they suffered so much to remain loyal to their God, but still maintained their faith.

The "keys of the kingdom" were given to St. Peter by Jesus Christ (according to the Gospel of St. Matthew). Catholics (and some other Christian denominations likewise) believe this was Jesus' way of denoting the "primacy" of Peter (compared to the other apostles) and that such primacy was to be passed down to his successors. It is believed that St. Peter was martyred in Rome, while he was the Bishop of Rome, so that specific office (Bishop of Rome) became the seat of primacy. This is how the Catholic church became affiliated with Rome to begin with. Even to this day, the Pope Carry's the title "Bishop of Rome".

To answer your question however, Catholics were not referred to as "Roman Catholics" until about 1950 in the spirit of political correctness as not to offend other schismatic groups who also claim to be "the/a Catholic Church". Most Catholics have adopted this term in order to differentiate with little hesitation while some of the more conservative ones insist that it is improper to both classify the Church's in communion with the papacy as "Roman" and to classify any other church as "Catholic". The loudest criticism of the Catholic church's exclusive use of the word "Catholic" doesn't however come from the older non-papal, liturgical worshipers (such as the Orthodox, Anglican, and Episcopalian churches) rather they come from the more recent schisms that tend to actually have the word "Catholic" in the name of their church (ex: The American Catholic Church, Liberal Catholic Church, etc).